An Historical Summary of Angelic Hierarchies from Part VII: The “Seven” Thrones in In Operibus Sigillo Dei Aemeth by David Richard Jones.

“These days, which abide in the interior light, may be taken for the angelic spirits, and the months, for their orders and dignities. For every single spirit, in that he shines, is a ‘day,’ but as they are distinguished by certain set dignities, so that there are some that are Thrones, some Dominions, some Principalities, and some Powers, according to this distribution of ranks, they are entitled ‘months.’

Moralia I:I:iv — Pope St. Gregory I” [via]

Consider also:

  1. “A similar, though less elaborate nine-fold celestial hierarchy was proposed by Pope Gregory I in his Gospel Homilies and in his Moralia on Job by collecting the Old Testament and Pauline references to angelic orders and arranging them by logical inference. We speak of nine orders of Angels, because we know, by the testimony of Holy Scripture, that there are the following: Angels, Archangels, Virtues, Powers, Principalities, Dominations, Thrones, Cherumbim and Seraphim. Nearly every page of Scripture is witness to the fact that there are Angels and Archangels. The prophetic books, as has been noted often, speak of Cherubim and Seraphim. Four more orders are enumerated by Paul the Apostle, writing to the Ephesians, when he says, ‘Above every Principality and Power and Virtue and Domination.’ And again writing to the Colossians, he says, ‘Whether Thrones, or Powers, or Principalities, or Dominations.’ When ,then, we add the Thrones to those he mentions to the Ephesians, there are five orders, to which are to be added Angels, Archangels, Cherubim and Seraphim, certainly making nine orders of Angels in all. Homily XXIV — Pope St. Gregory I”
  2. “It seems probable that this earlier genre of angelical classification is the source of Paul’s reference in Colossians. For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him: Colossians 1:16 (KJV) It is from this reference by St. Paul that all subsequent Christian theological discussions on the subject base their authority.”
  3. “St Paul’s usage of the term Thrones in this context indicates that it must have had meaning within then-current metaphysics. Though it is possible that the context of Colossians is an entirely mundane and political one, thones, and even dominions, principalities, and so on have been interpreted by subsequent Christian theologians in an almost entirely metaphysical way.”
  4. “Pseudo-Dionysus ranks the Thrones amongst the highest third of his nine (three by three ranking) orders of Celestial Beings and gives to them the function of showing forth the Divine Radiance. ‘The name of the most glorious and exalted Thrones denotes that which is exempt from and unattained by any base and earthly thing, and the super mundane ascent up the steep. For these have no part in that which is lowest, but dwell in fullest power, immovably and perfectly established in the Most High, and receive the Divine Immanence above al passion and matter, and manifest God, being attentively open to divine participations.’ Chapter VII: Of the Seraphim, Cherubim & Thrones & their first Hierarchy”
  5. “The earliest known reference to Thrones as an angelic order is found in the text of The Testament of Levi, in the pseudopigraphic collection referred to as The Testament of the Twelve Patriarchs. And in the highest of all dwelleth the Great Glory, far above all holiness. In the heaven next to it are the archangels, who minister and make propitiation to the Lord for all the sins of ignorance of the righteous; Offering to the Lord a sweet smelling savor, a reasonable and a bloodless offering. And in the heaven below this are the angels who bear answers to the angels of the presence of the Lord. And in the heaven next to this are thrones and dominions, in which always they offer praise to God. When, therefore, the Lord looketh upon us, all of us are shaken; yea, the heavens and the earth, and the abysses are shaken at the presence of His majesty. But the sons of men, having no perception of these things, sin and provoke the Most High. Testament of Levi I: 21–27 (trans. R.H. Charles)”